Component with a hub, and a non-cutting production method therefor

ABSTRACT

The invention relates to a method for non-cutting production of a component, especially a component of a gearbox. Said component comprises a hub ( 15 ). The hub ( 15 ) is provided with a stepped hole ( 15 ) and is produced by cold deformation in a pressing process. A hub ( 15 ) extending in a substantially radial manner with respect to the plane of a round metal blank is produced from a rotating round metal blank ( 1 ), using at least one rotating pressing cylinder ( 11 ). The invention is characterized in that the pressure cylinder ( 11 ) is advanced into the round metal blank ( 1 ) at least periodically and in sections, whereupon it is inserted therein in a radial manner from an outer position to an inner position. A material web ( 15 ) forming the stepped hole ( 17 ) and extending substantially inwards from the hub ( 15 ) is embodied on the inner periphery of the hub ( 15 ), characterized in that when the hub ( 15 ) is deformed, at least one section of an attachment ( 7 ) is arranged at a distance from the round metal blank ( 1 ). As the hub is formed ( 15 ), material from the round metal blank flows into the area between the round metal blank ( 1 ) and said section of the attachment ( 7 ).

[0001] The invention concerns a method for non-cutting manufacture of acomponent, in particular a gear part, with a hub, whereas the hub showsa stepped hole, thanks to cold-forming according to a compression methodwhich, using a rotary metal round blank with a through hole, forms thehub extending substantially radially to the plane of the metal roundblank by means of at least one rotary pressure roller so that thepressure roller is fed radially from the outside to the inside, engaginginto the metal round blank, at least intermittently and temporarily, aswell as a hub manufactured according to such a method.

[0002] This method of manufacture of a hub using a compression processis known since the patent WO 94/20235. This method is developed furtherin the patent DE 44 44 526 CI, according to the teaching thereof theexternal circumferential edge of the sheet plate is supported during thecompression process in order to provide an end lining resting againstthe circumferential edge of the metal round blank.

[0003] Moreover, it is known since the patent U.S. Pat. No. 5.951.44 aswell as parallel documents of the family of patents belonging to thisdocument, how to form a stepped hole, a so-called ‘blind hole’ intendedfor pulley hubs so that a stepped patch block shows a through hole suchthat an edge/a ring surface of the patch block resting at the outsidecircumference of the metal round blank held in the end lining, on themetal round blank and the portion of the patch block providing thethrough hole of the metal round blank exhibits an internal diametermatching the metal round blank. Thus, the provision of the hub leaves aninternal web at the hub, forming the stepped hole which is required bythe design in several applications or which can be machine faced inorder to confer a particular shape to the edges of the internal contour.The geometry of the stepped hole of the hub after compression alwaysmatches the thickness of the metal round blank in this area beforeausforming.

[0004] In the light of the technology available, the object of theinvention is to provide a method to manufacture hubs with stepped holegeometries which differ from the initial thickness of the metal roundblank in this domain, thereby breaking away from the technologyavailable.

[0005] The object of the invention is met by the characteristic of theclaim 1. A material web, extending substantially inwardly away from thehub, is formed at the inner circumference of the hub so that duringausforming of the hub at least a portion of a patch block is provided ata distance from the metal round blank whereas during the development ofthe hub, material of the metal round blank flows in the gap between themetal round blank and the patch block, thereby forming the stepped hole.

[0006] The invention differs from the patent U.S. Pat. No. 5,951,422inasmuch as the patch block rests directly on the round blank beforeausforming in order to prevent the material from flowing in the area ofthe stepped hole to be developed. It contradicts the teaching of thisdocument whereby it does not position the patch block at the round blankbut arranges said patch block to enable the material to flow even in thearea of inner diameter of the hub, whereas it is possible to confer avariable geometry to the hub in the area of the stepped hole, a variablegeometry which matches the shape of the patch block in the area of thestepped hole.

[0007] Thus, according to a preferred embodiment of the invention, thepatch block and/or the pin shows a widening diameter in the area of thethrough hole, outside the through hole, so that the area of the web isincreased when forming the hub, with respect to the initial thickness ofthe metal round blank, which was not possible with the patent U.S. Pat.No. 5,951,422.

[0008] According to another embodiment of the invention, the patch blockand/or the pin is provided in the area of the through hole with one orseveral diameter(s) which is/are smaller than the diameter of thethrough hole so that when developing the hub, material flows inwardlyfrom the inner diameter of the metal round blank and so that thediameter and/or the height of the web of the hub is reduced with respectto the initial thickness of the metal round blank. It is alsosurprisingly possible to make the web thinner with respect to itsthickness and smaller with respect to its diameter than the initialmaterial of the metal round blank if the metal round blank is fittedwith a matching large through hole wherein the patch block penetrateswith a stepped area. This was also not possible according to theteaching of the patent U.S. Pat. No. 5,951,422.

[0009] With respect to the technology provided by the patent U.S. Pat.No. 5,951,422, the number of embodiments can be increased significantlywhen building a hub out of a form of a metal round blank without makingthe manufacture of a hub properly speaking more complicated, since themetal ‘flows’ during the manufacture of the hub quasi ‘automatically’ inthe area between the metal round blank and the patch block arranged at adistance from said metal.

[0010] The inner circumferential web can take on any shape in the areaof the stepped hole using the invention. If the patch block is conicalin shape (at least in the area of the portion penetrating the throughhole) the web takes on a conical shape in this area. Similarly, othercontours can be developed in the area of the inner circumference, forexample various curves or gradations of different types.

[0011] The remaining characteristics of the claims will describe otheradvantageous embodiments of the invention.

[0012] The invention will be described more in detail with reference tothe appended drawings and to several embodiments, wherein:

[0013]FIGS. 1a,b illustrates a first embodiment of a method according tothe invention for the manufacture of a hub;

[0014]FIGS. 2a,b illustrates a second embodiment of a method accordingto the invention for the manufacture of a hub; and

[0015]FIG. 3 illustrates an embodiment of a method of manufacture of ahub according to the technology available.

[0016] FIGS. 1 to 3 illustrate a metal round blank (sheet plate) 1 whichis held by a tool 3 at its external circumferential whereas the throughhole 5 of the metal round blank is penetrated by a stepped patch block 7with a conical centring pin 8. As the gradation 9 is formed at adistance from the sheet metal round blank, it is not only the hub 15that is compressed during the motion of a rotary pressure roller 11 witha shoulder 13 to limit the radial extension from outside towards theinside, starting from the metal round blank, but material is alsocompressed between the patch block 7 and the metal round blank 3 inorder to provide the stepped hole 17 whereof the height of the web S isnow greater than the initial thickness B of the metal round blank. Thestepped hole 17 is also formed using material of the metal round blank 1whereas said material flows or is compressed from the metal round blank1 into the area of the stepped hole properly speaking.

[0017] Conversely, FIG. 2 illustrates a web height S2 which is smallerthan the thickness B of the metal round blank 1 whereas moreover thediameter of the stepped hole 17 is smaller than the diameter of thethrough hole of the metal round blank 1. For this embodiment, the roundblank 1 is fixed in the tool 3 at the external diameter and is fed withits gradation 9 into the through hole. The gradation 9 enables todevelop a stop edge or a stepped hole 17 with reduced diameter withrespect to the initial diameter of the round metal and with reducedheight of the web in the stepped hole 17.

[0018] Reference Signs Metal round blank  1 Tool  3 Through hole  5Patch block  7 Centring pin  8 Gradation  9 Pressure roller 11 Shoulder13 Hub 15 Stepped hole 17 Web width S1, S2 Metal round blank width B

1. A method for non-cutting manufacture of a component, in particular agear part, with a hub, whereas the hub shows a stepped hole, thanks tocold-forming according to a compression method whereby, a) using arotary metal round blank with a through hole, forms the hub extendingsubstantially radially to the plane of the metal round blank by means ofat least one rotary pressure roller so that the pressure roller is fedradially from the outside to the inside, b) at the inner circumferenceof the hub, a material web forming the stepped hole, extending from thehub substantially inwardly, is developed in such a way that duringausforming of the hub at least a portion of a patch block is provided ata distance from the metal round blank and that material of the metalround blank flows into the area between the metal round blank and thissection of the patch block when building the hub.
 2. A method accordingto claim 1, characterised in that a patch block with steps is used withat least two different diameters.
 3. A method according to claim 2,characterised in that a stepped patch block is used.
 4. A methodaccording to claim 2 or 3, characterised in that the patch blockexhibits an external contour with at least a partial conical and/orcurved shape.
 5. A method according to one of the previous claims,characterised in that the patch block or a pin formed separatelytherefrom penetrates the through hole of the metal round blank.
 6. Amethod according to one of the previous claims, characterised in thatthe patch block and/or the pin shows a widening diameter in the area ofthe through hole, outside the through hole, so that the area of the webis enlarged when producing the hub with respect to the initial width ofthe metal round blank.
 7. A method according to one of the previousclaims, characterised in that the patch block and/or the pin is fittedwith one or several diameter(s) in the area of the through hole, whichis/are smaller than the diameter of the through hole so that materialflows inwardly from the inner diameter of the metal round blank, duringthe manufacture of the hub, and whereas the diameter and/or the heightof the web of the hub is reduced with respect to the initial size of themetal round blank.
 8. A hub with a stepped hole, which is produced outof a metal round blank in a compression method according to one of theprevious claims, characterised in that the web forming the stepped hole(17) exhibits a height (S1, S2) extending axially with respect to theplane of the metal round blank (1), whereas said height is smaller orgreater than the thickness of the metal round blank (1).
 9. A hub with astepped hole, which is produced out of a metal round blank in acompression method according to one of the previous claims,characterised in that the inside diameter of the stepped hole (17)delineated by the web, is smaller than the diameter of the through hole(5).